Another solution is to use for example Ciphermail to automatically encrypt mail server-side. In this way you don't need to reject non-encrypted mail, you can just make sure it gets encrypted before it leaves premises.
-----Ursprungligt meddelande----- Från: dovecot-boun...@dovecot.org <dovecot-boun...@dovecot.org> För Austin Witmer Skickat: den 8 december 2021 07:15 Till: dove...@ptld.com; dovecot@dovecot.org Ämne: Re: Force clients to use pgp encryption when sending email? Thanks for that info! It’s just what I needed! > On Dec 7, 2021, at 8:35 PM, dove...@ptld.com wrote: > > >> >> Basically I want the server to check if the message being sent is encrypted >> with OpenGPG and either proceed or reject the message based on that criteria. > > > Postfix is your submission service so i think best to look that direction. If > there is a header you can check for (if the header exist then allow sending) > then postfix has header checks regexp/pcre that would be simple enough to > setup. > > On the more complex side, postfix also supports policy servers you can write > as a script (php, perl, python, etc) or you can go full on milter. > > > http://www.postfix.org/header_checks.5.html > http://www.postfix.org/SMTPD_POLICY_README.html > http://www.postfix.org/postconf.5.html#non_smtpd_milters
